1. Field of the Invention
This invention relates to rotation sensors of the kind sometimes referred to as solid state or vibrational gyroscopes. These differ from conventional gyroscopes in having no movable components.
2. Description of Related Art
One such vibrational gyroscope is described in U.K. Patent No. 2164749 which employs a cylindrical shell with a radial skirt or flange. The shell is driven to vibrate by electrodes positioned on a piezo-electric material deposited on the flat base. Transverse acoustic bending waves are thus transmitted around the shell in opposite directions and a standing wave pattern is set up. Rotation of the shell in conjunction with the travelling bending wave produces a Coriolis force which displaces the vibration nodal pattern to an extent which is related to the rate of rotation.
Such a sensor is ideal for `strap down` applications where movements are large and sudden. Relatively low sensitivity is therefore required but with considerable frequency response.